High speed paper advance system



yJuly 23, 1957 A. H. BLOCK 2,800,073

y HIGH SPEED PAPER ADVANCE SYSTEM Filed DBQ. 17. 1954 3 SheetSZSheet Aff/Men July 23, 1957 A. H. BLOCK l 2,800,073

- HIGH sPEED PAPER ADVANCE SYSTEMv E Filed DBO. 17, 1954 I5 Sheets-Sheet 2 July 23, 1957 Fil'ed D66. 17, 1954 A. H. lBLocK -2,800,073

HIGH SPEED PAPER ADVANCE SYSTEM y asneetsfsvneez 5 HIGH SPEED PAPER ADVANCE SYSTEM Arnold H. Block, Los Angeles, Calif., assignor to Hughes Aircraft Company, Culver City, Calif., a corporation of Delaware Application December 17, 1954, serial N. 475,931`

21 Claims. (Cl. lill- 93) The present invention relates to systems for advancing recording media and more particularly to a paper ad vance system for a high-speed printer that advances the paper at high speeds either intermittently, one line at a time, or continuously, a selected number of lines.

The advent of high-speed printers to legibly record information developed in the form of electrical signals by high-speed data processing machines has fostered the need for correspondingly high-speed paper advance systems to rapidly advance the paper, including carbon copies, upon which the information is printed. More specically, there,

has been an ever-increasing need in the printer art for a paper advance system that can quickly accelerate and decelerate the paper and accurately position it at'the high speeds required by high-speed printers without tearing' the paper. i

Controlled paper motion is obtained in one type of prior art paper advance system by selectively coupling the paper through a dogetype clutch to a driving .mechanism, such as a motor. The clutch essentially includes a toothed input member coupled to the motor and a similarly toothed output member coupled to the paper which Patented July 23, 1957 ice put members. Obviously, variations in the operating characteristics ofthe timing and control circuits will cause corresponding Variations inthe aforementioned periods of engagement and disengagement with the result that the spacing between printed lines will be unequal.

Smoother'intermittent and continuous paper motion is secured inanother type of paper advance system of the prior art by selectively coupling the paper to a motor through a slip-type clutch. The clutch basically includes a frictional input member coupled to the motor and a frictional output member coupled to the paper, the input is intermittently advanced by alternately engaging and disv engaging the toothed clutch members. More specifically, the paper is intermittently advanced one line at atime by periodically engaging the clutch members for a prede-A termined interval of time corresponding to theindvidual spacing between successive lines and slewed or "continuously advanced a selected number of lines by engag` the clutch members for equal periods of time and multiple i spaced by engaging the members for proportionately longer periods of time.

The prior art paper advance system mentioned above may be classified as an impact or brute force type of system wherein the clutch members are subject to relativelyY severe shock each time they are engaged and disengaged.

Accordingly, all elements of the system coupled to theclutch members are correspondingly subject to shock which significantly decreases the life expectancy of the clutch and associated elements. Furthermore, as a consequence, the paper is very sharply accelerated and decelerated so that the motion of the paper is compara-f tively jerky. Consequently, the speed of the paper mustV be limited to relatively low values to prevent the paper from being torn.

An additional disadvantage of a paper advance, system utilizing a dog-type clutch is that the clutch` inherently lacks the ability to accurately regulate the spacing be` tween lines to be printed. As a result, a system employing such a clutch must also include intricate timing and control circuits to measure and control the periods of engagement and disengagement of the clutch input and outand output membersbeing frictionally engaged for cou# pling the paper to the motor. As before, the spacing between successively printed lines of information? is determined entirely by the length of time the clutch members are engaged, the printed lines being single spaced by recurrently engaging the clutch members for equal periods of time and multiple spaced by engaging the members for proportionally longer periods of time.

A principal disadvantage of this prior art type of paper advance system is that friction is depended upon to engage the clutch output member to the input member. As a result, the output member slips with respect to the input member each time the clutch members are engaged and when the transmitted power becomes excessive so that digital positioning between them is lost. In other words, since the spacing between printed lines is determined solely by the period of engagement between the. clutch members, slippage' between the members results in` unequal spacing of the lines. Consequently, intricate error detection and timing circuits must be employed in the system to determine at all times and take into account the extent of the slippage between the members and to correct for it.

Furthermore, it will be recognized that, as in the paper advance system utilizing a dog-type clutch, a system using a slip-type clutch inherently lacks the power to control the spacing between the lines to be printed. Accordingly, another disadvantage of a system employing a slip-type clutch is that the system must include complex timing and control circuits to measure and control the periods of engagement and disengagement of the circuits. As mentioned previously, variations in the operating characteristics of the timing and control circuits will produce corresponding variations in the periods of engagement and disengagement of the clutch members with the result that the spacing between printed lines will be unequal.

The present invention overcomes the above and other disadvantages of the paper advance systems of the priory art by providing a paper advance system that accurately advances the paper at high speeds either intermittently, one line at a time, or continuously, a selected number of lines, without tearing the paper. According to the basic concept of the invention, controlled paper motion is obtained by coupling thepaper to a paper advance mechanism which, at all timestduring the printing operation,

is coupled through a clutch mechanism to a source of` entire printing operation for continuously rotating the shaft.y at a constant speed. A spider arm is mounted on the pow-.

er shaft and is selectively actuable under the control of an electro-mechanical detent mechanism for either rotating with the power shaftor remaining fixed with 'respect to a frame member. A Geneva drive mechanism is coupled to the power shaft and the spider arm and is actuable from either the power shaft or the arm, depending upon the energization of the detent mechanism, for advancing the paper either intermittently or continuously. Finally, a mechanical feedback mechanism is coupled between the arm and clutch for synchronizing ythe clutch with the output of the Geneva drive mechanism in .sucha manner that clutch disengagement and engagement for .stopping and starting the motion ofthe paper, respectively, can only occur :at afpre'determined point in .the printing cycle.

- One of the principal advantages of the .paperadvance i system of the present invention is Athat it advances l.the paper at high speed without tearing the paper. "During intermittent paper advance, the paper is quickly'brought from standstill to a relatively high maximum speed of advance and just as quickly returned to standstill. However,the paperis at first gradually vaccelerated from standstill and thenrapidly acceleratedsuntil the paper attains the maximum speed following which the Aorder 4of `motion-is reversed and the paper is at rstrapidly and then gradually decelerated to standstill. `Itwill be recognized that the gra'dualV initial acceleration and linal .deceleration of the paper from and to standstill vprovide transitional periodsof limited acceleration` and Ideceleration Vwhich prevent the paper from being subjectedto'excessive tearing stresses. During a slewing operation, 'the lpaper is continuously advanced aplurality of lines yat the maximum paper speed previously mentioned. However, the paper is accelerated to and decelerated from the maximum speed as `during intermittent paper advance. Consequently, during the slewing period, the transition from standstill to the slewing speed and back again to standstill is accomplished smoothly, that is, withlsubstantially no sudden acceleration or deceleration of the paper.

Another signicant -advantage inherent in the paper advance system of the` present invention is that the spacing between lines to be printed can accurately be regulated. The `Geneva drive mechanism includes `a rotatable starwheel having a predetermined plurality of indexing stations and a rotatable crank having a pin which is engageable with the stations. During each revolution of the crank, 'the pin engages a station to rotate the starwheel vexactly a vpredetermined .number of degrees equal to 360/n, where n is the number of stations of the starwheel. The paperis coupled to the starvvheel and is intermittently advanced equal increments during the periodioal rotations of the starwheel. Consequently, the present paper advancesystem equally spaces successively printed lines without the use of additional timing and control circuits required by the prior art ypaper advance systems.

An additionaladvantageof the paper advance system of Ithe present inventionV is that clutch engagement and disengagement for starting and stopping the motion Vof the paper can only occur at a predetermined'point in the printing cycle. Consequently, digital positioning yof the paper is never lost by discontinuing fthe motion 'of the paper. Furthermore, by selecting a suitable-point in the printing cycle for disengaging the clutch, ample time" is at all times provided subsequent to engagement lof the clutch for bringing the powervshaft to its operational speed and for replenishing the memory storage device-of the printer withinformation required for printing a line before thepaper is advanced to the next line to be printed. It is, therefore, an object of the present invention to provide an improved system for intermittently or continuously advancing a recording `medium at high speeds.

A It-is another `object of the present invention to'provide a paperfadvance Vsystem for a printer wherein the paper is selectively advanced either intermittently, one line at a time,'or continuously, a selected number of lines,while a paper advance system that selectively transforms the motion of a continuously rotating power shaft into intermittent or continuous motion of the paper.

It is ian additional object of the present invention to provide a paper advance system wherein the paper is intermittently advanced by tirst gradually and then rapidly accelerating the paper from standstill to a relatively high predetermined maximum speed following which the paper is rst rapidly and then gradually decelerated to standstill, the transitional periods of limited acceleration and deceleration permitting the paper to be advanced intermittently at high speeds without tearing by preventing the paper from being subjected to excessive tearing stresses.

It is still another object of the present invention to provide a paper Iadvance system wherein the paper is slewed at the maximum speed attained by the paper during a cycle of intermittent paper advance, the high slewing speed `of the paper being attained with a minimumof tearing stress by accelerating and decelerating the paper to and from the slewing speed, respectively, as in a cycle of intermittent paper advance.

It is yet another object of the present inventionto provide a paper advanceV system that is actuated and delactuated only at a predetermined point in the printing cycle.

The novel features which are believed to be characteristie of the invention, both as to its Vorganization and method of operation, together with further objects and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which an embodiment of the invention is illustrated by way of example. VIt is to be expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention.

Fig. 1 is a schematic diagram, partly in block form, ofapaper advance system according to the present invention;

Fig. 2 is `an elevation View, partly in cross-section, of the paper advance system shown in block form in Fig. l;

Fig. 3'is a sectional view of the spider arm included in the paper advance system of Fig. 2 taken along the line V3--3 ofFig. 2;

Fig 3a isa development Aof the outer surface of the section `tif-the spider arm shown in Fig. 3 in the direction of arrow A;

Fig. 3b is avdevelopmentrof surface a, IJ, c, d, e, of the'sec'tion of the'spider 'arm shown in Fig. 3 in the direction of arrow B;

Fig. 4 is a sectional view of the Geneva drive mech- 'anism of'thepaper advance system taken along the line 4-'44 of Fig. 2;

Fig. V5 is a Isectional view of a `gear train forming part of the paper advance -system taken along the line 5-5 offFig. 2 and illustrates a contact type of sensing device;

Fig, 6 is .a View in perspective of a photo-electric type ofsensing device; and

Fig. 7 'is a composite diagram illustrating the speed of the paper 4during various intermittent and continuous paper advance operations.

i 'Referring now to the drawings, there is shown in Fig. l a high-speed paper-advance system 10, according to the present invention, for advancing a paper printing'medium I1, ysuch as a paper strip, upon which lines of information are printed, either intermittently, one .line at a time, or continuously, la selected number of lines. Highspeed paper-advance system 10 is operable in conjunction with aj printer 12 and undei the control of electrical pulses received from an electrical control network '13, and comprises two `basic elements, namely; a'paper Vadvance mechanism 14 for advancing .paper strip 11 either intermittently or'continuously in response to electrical pulses selectively ppliedvby control network 13, anda `clutch mechanism asoo'pra mechanically coupled both to printer 12 andV paper advance mechanism 14 and responsive to an electrical pulse from the control network 13 for selectively intercoupling the printer with the paper advance mechanism.

`Control network 13 includes electronic circuits and mechanical components, not shown, for producing printing pulses representing the information to be printed, a control pulse for stopping and starting the paperadvance, and a slewing pulse for continuously advancing printing 'strip 11 a'selected number of lines. vBroadly stated, the function of control network 13 is to selectively actuate printer 12 to print the desired information, and to synchronizethe operation of the paper advance system with that of the printer. An example of the kind of circuits and components that may be used in control network 13 is disclosed in co-pending U. S. patent application, Serial No. 379,045, for A' High-Speed Printing System, by E. C. Nelson, filed September 8, 1953.

High-speed printer 12 is responsive to the printing pulses produced by control network 13 t-o print the desired information and includes four basic elements, namely; a drive mechanism, -such as a motor 16, a rotatable printing cylinder 17 mechanically coupled to motor 16,' a transducer network, including a plurality of selectively energizable printing transducers 18-1, 18-2 18-(n-2), 18-(n-1), and 18-n, and Ia traction mechanism 20. The printing transducers are positioned adjacent printing cylinder 17 and are adapted to lcooperate with the printing cylinder for printing the desired information on paper printing strip 11, while traction mechanism 20 includes sprocket wheels coupled to printing strip 11 through sprocket holes 21 uniformly distributed along the sides of the printing medium and is energizable from paper-advance mechanism 14 for applying the necessary force to the printing medium to advance the printing medium either intermittently or continuously under the control of the paper-advance mechanism.

Printing transducers 18-1, 18-2 18-(n-2), 18-(n-l), and 18-n are operable under the control of control network 13 and are preferably of the type disclosed in co-pending U. S. patent application, Serial No. 377,818, for High-Speed Electro-Mechanical Printing Transducers, by S. M. Fomenko et al., led September 1, 1953, now Patent No. 2,766,686. These transducers are preferred because of their relatively high e'ciency and their exceptionally high operating speeds. It will be recognized, however, that other printing transducers may beutilized with the high-speed paper-advance `system of the invention.

Printing cylinder 17 is preferably continuously rotated l by motor 16 and may be either a lskewed-type printing cylinder, similar to that disclosed in co-pending U. S. patent application, Serial No. 360,998, for Printing Cylinders for High-Speed Printing Systems, by R. A. Hartley, led June ll, 1953, now Patent No. 2,776,618, or a conventional straight-line type in which rows of type characters are longitudinally disposed about the periphery of the printing cylinder. In each of these two basic forms of printing cylinders, one row of type characters is provided for each. different type character which may be printed,. each row including a plurality of identical type characters corresponding in number to the number of printing transducers employed in the printer.

Traction mechanism 20 is mechanically coupled to paper-advance mechanism 14 and includes a plurality of sprockets engage-able'with the sprocket holes in paper printing medium 11 for moving the paper in accordance with the actuation of the paper-advance mechanism. When paper-advance mechanism 14 is operated for either intermittent or c-ontinuous advance of the paper, traction mechanism 20 is driven either intermittently or continuously and paper printing medium 11 is correspondingly advanced either intermittently or continuously. Any conventional type of traction mechanism may be employed With the present invention, such as the type known in the art as the Moore Formaliner which is commercially available from Moore Business IForms, Inc., of Nia-gara Falls, New York.

Referring now to Fig. 2, there i-s shown in detail paper-5 advance system 10, according to the invention, the system comprising, as previously stated, paper-advance mechanism 14 and clutch mechanism 15. Paper-advance mechanism 14 is responsive to rotation of `an input shaft 22 for selectively rotating an output shaft 23 either inter-l mittently or continuously under the Vcontrol of the slewing pulse impressed on an input terminal 24 by electrical control network 13 shown in Fig. 1. Input shaft 22 is driven by motor 16 through printing cylinder 17, power 'shaft 94 and clutch mechanism 15 ina manner to be described in detail hereinafter. It will be recognized that input shaft 22 also constitutes the output drive member of clutch mechanism 15, while output shaft 23 is connected to traction mechanism 20, as shown in Fig. 1, for

advancing the printing medium.

Essentially, paper-advance mechanism 14 includes a rotat-able power shaft 25 drivingly coupled to input shaft 22 through a gear train 26; an arm, generally designated 27, `mounted-on shaft 25 and selectively actuable under thepcontrol ofan electro-mechanical detent mechanism,

generally designated 28, for either rotating with shaft 25 or remaining xed with respect to a fixed frame member 30; a Geneva drive mechanism, generally designated 31,

which is coupled'to output shaft 23 through a gear train` 32 and which is actuable from either shaft 25 through a gear train 33 or from arm 27, depending upon the ener-Y gization of detent mechanism 28; and a mechanical feedback mechanism, generally designated 34, which is coupled between arm 27 and clutch mechanism 15 for synchronizing the clutch mechanism with the output of the paper advance mechanism in such a manner that clutch disengagement can only occur at a predetermined point in the paper 4advance cycle.

Power lshaft 25 has a slot 35 machined therethrough, :as shown in Figs. 2 and 3, and a hole 36 drilled in its right hand end and extending longitudinally from the` end of the shaft to slot 35. In addition a blind hole 37 has been drilled in shaft 25 on the opposite end of slot 35, this hole extending toward the left-hand end of the shaft, as viewed in Fig. 2.

Arm 27 is rotatably mounted on shaft 25 and includes a body member 38 having tan annular inner chamber 40 that surrounds shaft 25 adjacent slot 35, as shown in Fig. 2. Arm 27 may selectively be held either rigidly in position relative to frame 30 or fixed to the shaft for rotation therewith, and for this purpose includes an outer cam 41 integral with body member 38 and having a plurality of outer detents 42, and an inner cam 43 integral with body member 38 and having an inner detent 44. These cams and their associated detents are shown more clearly in Figs. 3, 3a, and 3b, Fig. 3 being a sectional view taken through plane 3 3 in Fig. 2. Arm 27 alsoincludes4 a gear 45 Xed on body member 38 and coupled through mechanical feedback mechanism 34 to clutchl outer cam 41, and graduated entrance 46 and exit 47 f j to .and from inner detent 44 will be explained more fully below in connection with the operation of the paper ad- Vance system.

, Electro-mechanical detent mechanism 28 includes a plunger type solenoid 48, an outer catch 50 positioned adjacent the outer cam of arm 27 and adaptable to engage the detents therein, and a plurality of links, generally designated 51, which mechanically couple the outer catch to the solenoid plunger. Links 51 are mounted on linkage pins Asuch :as pins, 52 and 53 'and are operable upon movement "of Athe Ysolenoid plunger in the direction' ,of arrow 54'to move outer `catch 50 'into engagement'with a preselected one of outer detents 42 on arm 27, as shown in Fig. 3. Y

Detent mechanism 28 also-includes a push `rodSS which is movable in hole `36, a spring actuated plunger 56 slidablymountedin blind hole' k37 and akey 57 rotatably mounted Yin the slot -35 ofshaft 25 `by a pin 58, push 'rod 55 being connected lto one end of links 51 and being movable forward or backward substantially along the axis of power shaft 25 whenrsolenoid l'48 is energized or tie-energized. `Key 57 is-maintainedinsubstantially point Contact with`the left Yhand-end of push rod 55 by the 'action of spring Lplunger 56, as shown 'gin Fig. 2, and is selectively moveable out of or into engagement with inner detent -44 4by the push rod Vwhen solenoid 48 is either energized orde-energized.

Geneva -drive 'mechanism l31 -is mechanically coupled to power shaft 25 and arm 27 and selectively transforms the JVrotational motion of the shaft'intoeither intermittent or continuous motion of the printing medium depending upon `whether solenoid 48 is energized or rie-energized. More-specifically, Geneva drive mechanism 31 comprises a drive unit, generally-designated 60, which includes a shaft 6-1 rotatably -journalled at one end of arm 27, a Geneva crank, generally designated62, integral with the other end of shaft-'61, and a gear 63 rigidly mounted on shaft 61 and in mesh with a gear 64 rigidly mounted on shaft 25. -Geneva crank-62, in\turn,`includesa body memb`er-65 anda drive-pin 66-protruding from the body member, pin 66 Abeing rotatable about the axis of shaft 61 in accordance with therotation of the shaft,the rotational speed of pin 66 Iand shaft 61 -being determined lby the rotational speed of shaft 25 and the gear ratio of gears 63 and-6:4.

- Geneva drive mechanism 31 also includes a driven member, generally designated 67, rotatably mounted on shaft 25, driven member 67 comprising a Geneva star wheel 63 and a gear 70'xed thereto, gear 7 G constituting a portion of Voutput gear train 32 for intercoupling the paper traction mechanism with the Geneva star wheel, Geneva star wheel68, as shown in greater detail in Fig. 4, includes 'a pllnality of indexing stations '71, each of the stations ,being sequentially engageable with pin 66 in a manner'suich that 4each revolution of shaft 25 rotates the st ar wheel a .predetermined number of degrees equal to 360 fdegrees divided by the number of stations. Rotation ojf the star wheel through this predetermined number of degrees, in turn, results in actuation of traction mechanism 20,.shown in Fig. l, to advance printing medium 1-1 one line.

-Mechanical feedback mechanism 34 includes a gear train 72 and a feedback shaft "/'Swhich is coupled through the -gear train to `arm 27; more particularly, gear train 7 2 comprises a driven gear 74 xedly mounted on feedback shaft 73 and an 'idler gear 75 rotatably mounted on input-shaft 22, idler gear'75 being meshed both to driven gear 74 and to gear 45 of Iarm 27 for coupling the feedbackshaft to the arm, as mentioned above.

`In addition to the basic structure of paper advance mechanism 14 as set forth above, the paper advance mechanism preferably `also includes a sensing device for synchronizingthe position of paper printing medium 11 to ythe vsystem iprinting cycle as will be described more fullybelow. Two different types of sensing kdevices have been found to be readily utilizable with the paper advance Vsystemof the present invention, one type being termed a contact type sensing device and the other type being'termed a photoelectric type sensing device.

One Isuitable type of contact type sensing device is shown in Fig. and includes apair of gears, which may be gears 63 Vand 64 shown in Fig. 2,-each gear 63 and 64 having on its lateral Vsurfacea conducting ring 76 and nected througha secondfbrush contactSl to anoutputV terminal 82v which'is connected to control network `13.

The teeth of lgear t64, except for tooth 82, andthe teeth of gear 63, except Vfor portions of adjoining -teeth 83'and84, are madeflofan electrically insulatingmaterial,

while tooth 8,2 and the aforementioned 4portions of teeth 83 and 84 are made of an electrically conducting material, as shown in Figs. 2 and 5. Furthermore, gears-63 andv 64 aremeshedtogether'in Vsuch a manner that'tooth 82 meshes once withteeth 83 'and`84 during each revolution ofthe gears, V`thereby completing the-electrical circuit between vbattery'8i) and-contrOl-.network l13 -to causeran electrical signal to be applied to the .control-network. By properly relating the meshing-of the electrically-conductive teeth with the actuation of the Geneva drive mechanism, the electrical signal maybe made to coincide intime with the completion Iof the advance of paper printing medium 11. Consequently, the electrical signal may be `used in control network `13 to indicate when the printing signals produced by the ,control network-are to be applied to the associated printing transducers for printing the next line of information on the paper printing medium.

- Referring now to Fig. 26, there is shown a perspective view of one Vform-of a'photoelectric `type of sensing device which maybe employed with the paper advance mechanism of the invention. This sensing device comprises a disk 85 secured rto power shaft 25 and having a plurality of evenly spacedradial slits`86 cut in its periphery, the number ,of slits preferably being equal to the number of `indexingstations in star wheel68. Thissensing device also includes a source of light 87 for projecting a thin beamiof lighttowardthe periphery o'f-disk 85 and a-photocell 88 disposed on the opposite side of the disk, the photocell being ,electrically connected between ground and an output terminal 90 which `is connected to control network k13. Photocell 88 is resposive to light passed through the slits-in disk 85 for applying electricalpulses to the control network. Dick 85 is fixed to shaft 25, as shown schematically in Fig. 6, and is rotatable in accordance with rotation of Vstar'wheel 68. In order to provide proper timing between the indexing movement and the light bearn,'the relative position of light source87 and photocell 88 with respect to yslits 86of disk 85 is such that the beam normally impinges upon disk 85 midway between neighboring slits and is allowed to impinge upon photocell 88 only when a slit isrotatedpast the beam. As will be understood more completely from the description of operation set forth below, a slit is directly beneath the light beam midway during the advance of paper printing medium 11 to the next line to be printed, at which time the light beam impinges upon the photocell and an electrical pulse is applied to control network 13.

It will be recognized that although the electrical pulse is generated prior to the completion of the paper advance operation, the pulse may be delayed by a suitable delay network, not shown, so that the electrical pulse corresponds to any selected instant in the printing cycle, such as the moment thepaper completes its advanceto the next line to be printed. Accordingly, the electrical pulse may be used in control network 13 to-indicate when the printing signals, produced by the control network, are to be applied to the printing transducers for printing the next line of information. Y

Referring again to paper advance system 10 of Fig. 2, clutch mechanism 15, which is mechanically coupled, as previously explained, between paper advance mechanism 14 and type cylinder 17 shown in Fig. l, essentially comprises a single-revolution clutch, generally designated 91, for obtaining automatic, positive, substantially non-slipping motor drive .for the paper-.advance mechanism and whichl permits rotation of the `drivenpart in one direction 9 only, and a clutch disengage from its motor drive at a predetermined point in the cycle of operation.

Single-revolution clutch 91 is shown schematically and includes an input driving member 93 lixedly mounted. on a driving shaft 94 which connects the driving member through type cylinder 17 to motor 16 and an output or driven member 95 fixedly attached to input shaft 224 which connects-the driven member to the paper advance' mechanism through output shaft 23. Clutch 91 also includes a plurality of clutch rollers 9.6 positioned between driving and driven members 93 and 95 and a rotatable clutch cage 97 for selectively positioning clutch rollers 96 to either drivingly couple driving member 93 to driven member 95 or to disengage the driving and driven mema bers. In addition, a trip pin 98 is attached to clutch cage 97 substantially as shown and is rotatable with the clutch cage about shaft 22 when the driving and driven members of the clutch are engaged. Illustrations and descriptions of several different types of single-revolution clutches which may be utilized in the system of the invention, to. gether with auxiliary mechanisms, may be `found in the brochure, entitled The Hilliard Single-Revolution Clutch,, Bulletin 239, publishd by the Hilliard Corporation of El` mira, New York.

ed on the feedback shaft.

control pulse applied to an input terminal 106 by control network 13 of Fig. l for sliding gear 100 along shaft 22 until the gear butts against a pair of pimples 107 on the shaft. As a result, stop pin 103 is projected into the path of rotation of trip pin 98, the engagement of pins 98 and 103 resulting in the decoupling of driving and driven members 93 and 95, respectively, by disengaging, clutch rollers 96 from the driving and driven members,.

thereby disconnecting paper-advance mechanism 14 from its motor drive. It should be noted that in order to propi erly reference single-revolution clutch 91 with output shaft 23, the gear ratio between gear 100 and gear 45 of arm 27 preferably is 1:1.

In discussing the operation of the paper-advance sys-A tem shown in Fig. 2, it will arbitrarily be assumed as an `50 14 is coupled through clutch mechanism 15 and type cylinitial operating condition that paper advance mechanism inder 17 to motor 16 and that paper printing medium 11 is being advanced intermittently, one line at a time. Ac-

cordingly, shaft 25 of paper advance mechanismV14 is rotating ata constant speed and arm 27 is held in a fixed position with respect to the shaft by electro-mechanical detent mechanism 28. de-energized so that outer catch 50 is engaged with one of outer detents 42 of outercam 41 as shown in Fig. 3.

Simultaneously, key 57 is maintained in its disengaged position with respect to inner detent 44 of inner kcam 43 by push rod 55 which has been pushed forward in hole 36 by the de-energized solenoid.

Owing to the fact the arm 27 is held stationary with respect to frame 30 during intermittent paper advance, gears 63 and 64 function to rotate drive member 60 of Geneva drive mechanism 31 at a constant speed aboutV the axis of shaft 61. Accordingly, pin 66 of drive member 60 is rotated at a constant speed about the axis of shaft 61 and, during each revolution, engages a station 71 of Geneva starwheel 68 to rotate the starwheel a predetermined number of degrees equal to' 360/n, where n is the number of stations in the starwheel. Intermittent rotation of starwheel 68, in turn, results in intermittent rotation of output shaft 23 so that paper mechanism, generally desig-V nated 92, for disconnecting the paper advance mechanism More specifically, solenoid 48`istraction mechanism 20 of Fig. 1 is intermittently actupaper are accelerated from standstill to a maximum4 speed and then decelerated to standstill. These varial tions in ,speed are shown by curve 108 in Fig. 7 and, as

may be seen therefrom, prior to instant t1, which represents the initial engagement of a starwheel station byV pin 66, starwheel 68 and paper 11 are at zero speed and a line of information is being printed upon the paper. At instant t1, a starwheel station 71 is engaged by pin 66, at which instant starwheel 68and paper 11 are accelerated until they reach a maximum speed at instant t2, as indicated by point of curve 108.

Following instant t2, starwheel 68 and paper printing medium 11 are decelerated until, at instant t3, the starwheel and the paper are again at zero speed. It should bel noted that point 110 is midway between instants t1 and t, `and that, at point 110, starwheel 68 is rotating about the axis of shaft 25 at the same speed as the shaft. Between instants ta and t4, starwheel 68 and paper printing medium 11 remain at zero speed, that is, stationary, and control network 13 applies printing signals to the printing transducers for printing information upon the line rto which the paper has been advanced. At instant t4, the line of information has been printed and starwheel 68 and paper 11 are again accelerated and decelerated, as previously described for the time interval from t1 to t3. Thus, each cycle of intermittent operation cornprises first andv second intervals of time, a rst interval for printing information upon the paper printing medium and a second interval for advancing the paper to the next line to be printed.

It should be noted that if paper advance mechanism 14-includes a contact type of sensing device, such as that shown in Fig. 5, an electrical pulse is produced by the sensing device and applied to control network 13 at the end of the second time interval, that is, at instant t3, to indicate that the printing signals produced by the control net-work should be applied to the printing transducers. On the other hand, if paper advance mechanism 14 includes a photoelectric type of sensing device, such as that shown in Fig. 6, the electrical pulse produced by the sensing device is applied to` control network 13 in the middle of the second time interval, that is, at instant t2. Since point 110 of curve 108, as shown in Fig. 7, coincides in time with instant t2, it will at once be recognized that the electrical pulse produced by the sensing device coincides in time with point 110 at which time starwheel 68 and paper 11 have attained their maximum speed of rotation and advance, respectively.

When the photo-electric sensing device is utilized, control network 13 preferably includes a delay network, such as an electronic counter supplied with suitable timing pulses, for measuring off the time interval from t2 to t, to indicate when the paper advance operation has been completed and when the printing signals produced by the control network may be applied to the printing transducers.

Consider now the operation of paper advance mechanism 14 when it is desired to slew the paper printing medium, that is, to continuously advance the paper a selected number of lines from the last line of information printed. For purposes of description, reference is made to curve 111 of Fig. 7 which illustrates the variations of speed of starwheel 68 and paper strip 11 during a specific slewing operation in which the paper is continuously advanced two lines from the last line printed. Accordingly, at instant t5 arm 27 is held in a fixed position with respect to shaft 25 and a complete line of information has been printed on paper printing mediumrll. Furthermore, at instant t,i a station 71 is initially .engaged by pin 66 and starwheel 6,8 and paper 11 are accelerated from standstill atinstant t5 to a maximum speed of rotation and advance, respectively, at instant t, as shown by vpoint 1'12 on .curve `1,11 and as previously described for time interval t1 to t2 of curve 108. Assume now that .during the interval between instant t5 andl instant t6, preferably not too close to instant tu, a slewing pulse is applied to input terminal' '24. by control network `13 of Fig. l to energize solenoid 48. When solenoid 48 is energized, links 51 of electro-mechanical detent mechanism 23 move toward the right and hence function to try to move outer catch 50 out of engagement with outer 'detent 42 of outer cam 41, ,as shown in Figs. 3 and 3a, Simultaneously, links `51 tend to rotate key 57 into engagement with inner detent 44 of Vinner cam 43 by partially withdrawingwpush-rod 55 from hole 36 It will be recognized, however, from Figs. 2, V3a and 3b, that ,catch 50 cannot move out of engagement with outer detent' .42 until key 57 is engaged with inner detent 44. y'lt will also be recognized that key 57 cannot engage detent 44 until the key, which is rotating with shaft 25, is aligned with inner detent 44, which is held stationary by virtue ,of the stationary position of arm 27. Accordingly, if the slewing pulse is applied immediately after instantz5 (Fig. 7) key 57 is urged forward into engagement with .graduated approach 46, as shown in Fig. 3b, and slides in the direction of arrow 120 along the approach until the key is aligned with inner detent 44 at instant t6, at which time the key slides into the inner detent to rigidly connect arm 27 to shaft A25 while catch 50 is moved clear of outer detent 42. Hence, arm 27 will now rotate with shaft 25.

The engagement of arm 27 with power shaft 25 forces the arm and drive member 60 mounted on the arrn to rotate with shaft at the same constant rotational speed of the shaft. Consequently, pin 66, which is engaged with a starv/heel station 71, locks the starwheel to `shaft 25 through drive member 60 and arm 27 and causes the starwheel to rotate at the speed of the shaft. Morever, since the maximum speed of rotation attained by starwheel 63 at instant ts is equal to the speed of shaft 25, the locking of the starwheel with the shaft is accomplished smoothly, that is, with substantially no acceleration of the starwheel or the paper traction mechanism.

It will be noted that if paper printing medium 11 is continuously advanced two lines, the'constant rotational speed of the starwheel is.only maintained for a period suicient to advance the printing medium one line, since the acceleration and deceleration periods of thestarwheel each function to advance the paper onehalf a line. Consequently, after instant te, Vstarwheel 68 istrotated at the speed of shaft 25 and paper 11 is concomitantly uniformly advanced at a maximum speed until instant t corresponding to point 113 of kcurve 111, at which time the paper has been advanced one and one half lines since instant t5. After instant t7, the starwheel, the paper traction mechanism, and the paper are again decelerated to a point of zero velocity at instant t, in a manner to be presently explained, the deceleration period serving to advance the paper a nal half line so that its total advance equals the desired two lines.

Consider now the operation of paper advance mechanism 14 in switching from uniform paper advance prior to instant t, to a decelerating advance after -instantttp At some point during the interval between instants tand t7, preferably not too close to instant t7, the slewing pulse applied to input terminal 24 by electrical control network 13 is terminated and solenoid 4S is again `deenergized, the .de-energized solenoid tending to move catch S0 into engagement Iwith a detent 420i outer-cam 41 and to move Vkey S7 out of engagement with inner detent 44 of inner cam 43, as shown in Figs. -3, 3a and 3b. Accordingly, key V57 starts to move out of inner detent 44 .but is restrained from leaving the detentlcompletely by reason of the 1fact that catch 5.0 rides along one of the spil-ally curved surfaces .of outer cam 41 until eatch ,50"is. aligned -with an outer detent 42.

"It should 'be pointed out that in the presentinstance, whereinqthe` paper is being `slewedtwo lines, the outer detent engaged'will'be the onefollowing the. detent which was ldisengaged ,prior -to instant te. It should also be pointed 'out that catch '5 0 ,engage/s. the outer detent at the precise instant. that the paper has. completed an advance of ,one line Vat uniform speed, this instant, being instant t7. f,Graduated...exit.147, .as Shown in Fig. 3 b, is designed so that keyVV 57 -is Vmoved free of inner detent 44 at the sarne time. that Aouter catch 50 initially engages outer detent 42, therebyprecluding thepossibility that either the outer catch 7or, the `key .-Willbe ,broken by being engaged at the returns rthe ,armto its. stationary position.

rIt will Vbe remembered that at instant tmthat is, at the instantstarwheel 168 was .looked through drive member 6.0 and .arm 27 Ato shaft. 25, pin 66 was completely within station 7.1, .as-shownin Fig. 4. Pin 66 remains in this position relative to the. starwheelduring the time `interval from te to` 14,-and -iS permitted to rwithdraw `from the station only after instant t7 when` arm 27 is disengaged fromshaft .25. At instant t7, therefore, drive member 6.0,begins to rotate about the axis of shaft 61 and pin 66 beginsits withdrawal from the. starwheel station, thereby decelerating the starwheel and, consequently, paper print ingl mediumll. ,Starwheel68 and paper 11 are smoothly.fdec eleratedrfrom a maximum speed of rotation and advance, respectively, -at instant t7, to standstill at instant t,.as previously .discussed for the time interval from 2 to .t3 ofcurve t10S, thereby completing the slewing operation Ain 4which lthe .paperis continuously advanced two lines.

Assuming that thecontact type of Vsensing device shown in Eig. ..5 is'being used with ,paper adv-ance mechanism 14, the sensingdevice applies'a pulse -to control-network-13 at instant t, to indicate that the printing pulses produced by the control-,network .frnay be applied to printing transducers 18-1,18-.2, 18401-2), l'-(n-l), 18-nto print the next line of information. Starwheel 68and paper printing medium 1'1 lremain stationary yfrom instant ts'until instant tD and, during this periodwhich has heretofore lbeen termed the first time interval, the line of information is printed. Following instant t9, paper 11 `may again be Vintermitt,ently advanc ed,as` illustrated by thatl portion of curve y111 shown betweeninstants t, and t10 and as Vpreviously V'discussed in connection with the operation ofthe paper advance mechanism 'during intermittent paper advance.

.It will be obvious from the foregoing discussion of a slewing operation, in which: paper .printing medium 11. was continuously advanced two lines, vthat paper advance system 14 may be employed to slew the printing medium any desired number of lines. Curve 114 in Fig. 7, for example, is illustrative or" a slewing operation in which paper printing medium 11 is continuously advanced three lines. It will be noted from curve V114 that `the paper is accelerated from a stationary position at instant t1, to a maximum lspeed of advance at instant im, advanced two `linesat this maximum speed until instant 113, and

then decelerated to a stationary Vposition at instant tm, in the ,manner.previouslydescribed l It should .benoted :.that an inherent characteristic of Geneva drivemechanisrn 31 is thatthe maximum speed of.rotation to .which starwheel .68 Yis accelerated is proximately twice the average speed ofV rotation of the starwheel during an intermittent rotation period in which paper printing medium 1p1 is advanced one line. In other words, with reference to curve 108 of Fig. 7, at point 110, corresponding to instant t2, the speed of rotation of starwheel 68 is twice the average speed of rotation of the starwheel during the time interval between instants t, and t8.

In a similar mannerit will be recognized that the maximum speed of advance to which paper printing medium llis accelerated is twice the average speed of the paper during one intermittent paper advance period.

Accordingly, in the interval between the initial and final` periods of acceleration and deceleration of the paper during a slewing operation, the paper is advanced two lines in the time required to advance the paper one line during intermittent motion. For example, paper printing medium 11 is advanced two lines during the time interval from t12 to t1, of curve 114 and is advanced only one line during the time interval from t1 to t, of curve 108, although the two time intervals are equal. Since shafts 25 and 61 may be rotated at very high speeds and since starwheel 68 may have a relatively large number of drive or indexing stations, it will at once be obvivous that the paper advance system of the invention provides the high-speed paper advance required for modern high-speed printers.

Continuing now with the operation of paper advance system as shown in Fig. 2, assume that paper printing medium 11 is again being intermittently advanced one line at a time and that it is desired to entirely discontinue or stop the motion of the paper. Accordingly, referring to clutch mechanism 15, a control pulse is applied to input terminal 106 by control network 13 of Fig. l for deenergizing solenoid 105. In response thereto, linkage 104 is rotated toward clutch 91 to slide gear 100 against pimples 107. As a result, stop pin 103 is projected into the path of rotation of trip pin 98, the engagement of pins 98 and 103 resulting in the decoupling of driving and driven members 93kand 95, thereby disconnecting the paper advance mechanism from its source of power.

Prior to stopping the paper motion and while the paper is being intermittently advanced, trip pin 98 of clutch mechanism 15 and pin 66 of Geneva drive mechanism 31 are rotating at the same speed around shafts 22 and 61, respectively, pin 98, as shown in Fig. 2, being at a high point in its circular path around shaft 22 when pin 66 is completely in a station of starwheel 68 and, 180 degrees later, at a low point in its path when pin 66 is atthe furthest point from a starwheel station. Furthermore, stop pin 103 is positioned relative to trip pin 98 so that engagement of pins 98 and 103 can occur only when pin 98 is at a low point in its path. Accordingly, driving and driven members 93 and 95 are decoupled and pin 66 ceases to rotate only when pin 66 is at the furthest point in its path from a starwheel station.

During a slewing operation, when arm 27 rotates Geneva drive mechanism 31 a selected number of degrees around shaft 25, as previously explained, arm 27, acting through feedback mechanism 34, also rotates gear 100 an equal number of degrees around shaft 22 in the same direction as that of the Geneva drive mechanism. Consequently, the above-mentioned positional relationship between pins 98 and 103 is maintained and, upon a return to intermittent paper advance, the engagement of pins 93 and 103 can occur only when pin 66 is at the furthest point in its path from a starwheel station.

When it is desired to again print information on paper printing medium 11, a control signal is again applied to input terminal 106 by control network 13 of Fig. l, and in response thereto, solenoid 105 is energized to rotate linkage 104 away from clutch 91. As a result, trip pin 98 is disengaged from stop pin 103 and driving member 93 is coupled to driven member 95. Thus, the paper advance mechanism is coupled to its source of power and pin 66 commences to rotate from its stopping point tol' ward a station of starwheel` 68, the interval of time elaps ing until the paper is advanced to the next line to be" printed being used'to replenish the memory storage device of the printer withthe information to be printed andi to bring shaft 25 `to itsconstant operational speed.

What is claimed as new is:

1. A system for advancing a recording medium upon which lines of informationare to be recorded, said sys-4 tem comprising: a source ofmechanical energy; mecha nism mechanically coupled between the recording mediuni and said source for normally cyclically advancing the recording mediumvone `line at a time, each cyclical advance including a point of maximum velocity; and means for producing a signalL at a selected one of said points ofv maximum velocity, said mechanism being coupled to said means and operable in response to said signal for continuously advancing the recording medium a selected` number ofV lines at said maximum velocity. Y

2. In a high speed printer wherein lines of information are to be printed on a printing medium, a system for` advancing said printing medium, said system comprising: electrical control means for producing first and second signals; a source of mechanical energy; drive means mechanically coupled to the printing medium and electrically coupled to saidrelectrical control means, said drive means being energizable from said source 4for cyclically advancing the printingimedium oneliue at a time and, in re. sponse to said first signal, for continuously advancing the printing medium a selected number of lines; and clutch means mechanicallycoupled between said source and said drive means for normally energizing said drive; means, ,said clutch means being operable in response to. said second signal for de-energizing said drive means.

3. In a high speed printer wherein lines of information are to be printed on a printing medium, a system-for advancing said printing medium, said system comprising: electrical control means for producing first and second signals; a source of mechanical energy; drive means mechanically coupled to the printing medium and electricallycoupled to said electrical control means, said drive means being energizable from said source for cyclically advancing the printing medium one line at a time and, in response to said first signal, for continuously advancing the printing medium a selected number of lines, each cyclical advance of the medium including first and second predetermined intervals of time, a line of information being printed during said first interval of time and the printing medium being advanced to the next line to be printed during said second interval of time; and clutch means mechanically coupled between said source and said drive means for normally energizing said drive means, said clutch means being operable in response to said second signal for de-energizing said drive means.

4. The system defined in claim 3 wherein said clutch means includes selectively operable decoupling means responsive to said second signal for de-energizing said drive means at a predetermined instant during said first interval of time.

5. The system defined in claim 4 wherein said drive means includes feedback means coupled to said decoupling means for synchronizing said decoupling means with the advance of the printing medium in such a manner that de-energization of said drive means can only occur at the predetermined instant during said first interval of time.

6. In a high speed printing system for printing lines of information upon a printing medium, each line having a predetermined plurality of characters, the combination comprising: electrical control means for producing printing and slewing pulses; a plurality of printing transducers corresponding to the plurality of characters in a line of information to be printed and electrically connected to said control means, said transducers being positioned adtending through the printing medium along the Vline to be printed and selectively energizable in response to said printing pulses for'striking said adjacent surface of the printing medium; a printing cylinder rotatable about an axis in the plane of said transducers, said cylinder being positioned adjacent the other surface of the printing medium and having a series of rows of type characters longitudinally disposed about the periphery thereof, each of said rows corresponding to a different character to be printed and including a plurality of identical type characters corresponding to said plurality of transducers; means mechanically coupled to said printing cylinder for rotating said cylinder at a constant speed to sequentially pass each row of type characters `beneath said transducers; and drive means mechanically coupled between the printing medium and said printing cylinder for cyclically advancing the printing medium one line at a time, said drive means being selectively operable in response to said slewing pulses for continuously advancing the printing medium a selected number of lines.

7. In a high speed printing system for printing lines of information upon a printing medium, each line having a predetermined plurality of characters, the combination comprising: electrical control means for producingprinting and slewing pulses; a plurality of printing transducers corresponding to the plurality of characters in a line of information to be printed and electrically connected to said control means, said transducers being positioned adjacent one surface of the printing medium in a plane extending through the printing medium along the line to be printed and selectively energizable in response to said printing pulses for striking said adjacent surface of the printing medium; a printingV cylinder rotatable about an axis in the plane of said transducers, said cylinder being positioned adjacent the other surface of the printing medium and having a series of rows of type characters longitudinally disposed about .the periphery thereof, each of said rows corresponding to a different character to be printed and including a plurality of identical type characters corresponding to said plurality of transducers; means mechanically coupled to said printing. cylinder for rotating said cylinder at a constant Vspeed to sequentially pass each row of type characters kbeneath said transducers; and drive means mechanically coupled `between the printing medium and said printing cylinder for cyclically. advancing the printing medium one line at a time, each cyclical advance including a first interval of time for printmg a line of information and la second interval of time for accelerating the medium from Zero speed to a maximum and thereafter decelerating the medium again .to advance the lmedium to they next line to be printed, Vsaid drive means being selectively operable in response to a slewing rlnedium at said maximum speed fora selected number `of rues.

8. The combination defined in claim 7 wherein saidV drive means includes sensing means for producing an electrical pulse at the end of said second interval of time.

9. The combination defined in claim 7 wherein said drive means includes sensing means for producing an electrical pulse at an instant of time during said second interval of time having la kfixed time relationship with respect to the 4end lof said second interval.

l0. In a paper advance system wherein the paper is normally intermittently advanced one line at a time and, in response to a slewing signal, continuously advanced a selected `number of Elines, a paper advance mechanism, said mechanism'comprising: a shaft rotatable about its'axis; a source of power coupled to said shaft for rotating said shaft about said axis ata constant speed; an arm rotatably mounted on said shaft; means for selectively holding said arm stationary on said shaft or fixing said arm to said shaft for rotation therewith, said means normally 'holding said arm stationary and being responsive to the slewing signal Ko t,

pulse produced at an instant of maximum speed 1n a selected cycle to continuously advance the printing for fixing said arm to said shaft to rotate said arm about said axis at saidconstant speed; and paper advance means mechanically coupled to said shaft and said arm for advancing the paper, said paper advance means intermittently advancing the paper one line at a time when said arm `is held stationary by said means and continuously advancing the paper the selected number of lines when said arm is fixed to said shaft by said means.

ll. In a paper advance system whereinthe paper is normally intermittently advanced one line at a time and, in response to a slewing signal, continuously advanced a selected number of lines, a paper advance mechanism, said mechanism comprising: a shaft rotatable about its axis; input means coupled-to said shaft for rotating said-shaft about rsaid axis at a constant speed; an arm rotatably mounted on said shaft; electro-mechanical means for selectively holding said arm stationary on said shaft or fixing said arm to saidshaft for rotation therewith, said electro-mechanical means normally holding said arm stationary and being responsive to the slewing signal for fixing said arm to said shaft to rotate said arm about said axisat said constant speed; and output means mechanically coupled toy saidshaft and said arm for advancing the paper, said output means intermittently advancing the paper one line at a time when said arm is held stationary by said electro-mechanical means and continuously advancing the paper the selected number of lines when said arm is fixed kto said shaft by said electro-mechanical means.

vl2. In a paper advance system wherein the paper is normally intermittently advanced one line at a time and, in response to a slewing pulse, continuously advanced a selected number of lines, a paper advance mechanism, said mechanism comprising: a shaft rotatable about its axis; input means mechanically coupled to said shaft for rotating said shaft about said axis at a constant speed; an arm rotatablyfmounted onvsaid shaft; electro-mechanical means for selectively Vholding said arm stationary on said shaft or for fixing said. arm to saidV shaft for rotation therewith, said electro-mechanical means normally holding said arm stationary and being responsive to ,the slewing pulse for xing `said arm to said shaft to rotate said arm with said shaft at said constant speed; a driven member rotatably mounted on said shaft and mechanically coupled to the paper for advancing the paper, said driven memberbeing periodically rotatable through a fixed predetermined angle to intermittently advance the paper one line at a time and being rotatablethrough a selected angle corresponding to the selected number of lines for continuously advancing the paper the selected number of lines; and driver means rotatably mounted on said arm and mechanically coupled to said shaft for periodically rotating said driven member through said fixed predetermined angle and for rotating said driven member through said selected angle, said driver means having a driver axis and being rotated about said driver axis for periodically rotating said driven member through said fixed predetermined angle when said armis held stationary by said electro-mechanical means ,and being rotated about said shaft axis for rotating said driven member through said selected angle when said arm is fixed to said shaft by said electro-mechanical means.

13. The paper advance mechanism defined in claim 12 wherein said driven member further includes electrical contact means for periodically producing an electrical pulse corresponding to a predetermined instant during each intermittent advance of the paper.

14. The paper advance mechanism defined in claim 12 wherein said mechanism further includes photoelectric sensing means coupled to said driven member for producing an electrical pulse at a predetermined instantduring each intermittent advance of the paper.

15. AIn a paper advance system wherein the paper is normally cyclically advanced one line at a time and,` in response to a slewing signal, continuously advanced a predetermined number of lines, a paper advance mechanism, said mechanism comprising: a fixed frame; a shaft rotatable about its axis; input means mechanically coupled to said shaft for rotating said shaft about said axis at a constant speed; an arm rotatably mounted on said shaft; electro-mechanical means for selectively connecting said arm to said frame or to said shaft, said electromechanical means normally connecting said arm to -said frame and being responsive to the slewing pulse for simultaneously disconnecting said arm from said frame and connecting said arm to said shaft; a Geneva starwheel rotatably mounted on said shaft and mechanically coupled to the paper; and driver means rotatably mounted on said arm and mechanically coupled to said shaft, said driver means rendering said Geneva starwheel oper able to cyclically advance the paper when said arm is connected to said frame and to continuously advance the paper for the selected number of lines when said arm is rigidly connected to said shaft.

16. The paper advance mechanism defined in claim wherein said arm includes an outer cam having a predetermined number of outer detents and an inner cam having an inner detent.

17. The paper advance mechanism defined in claim 15 wherein said electro-mechanical means includes a solenoid, an outer catch and an inner catch coupled to said solenoid and operable thereby, said outer catch being rotatably connected to said frame for connecting said arm to said frame, and said inner catch being rotatably connected to said shaft for connecting said arm to said shaft.

18. The paper advance mechanism defined in claim 15 wherein said arm includes an outer ca m having a predetermined number of outer detents and an inner cam having an inner detent; and said electro-mechanical means includes an outer catch rotatably connected to said frame and being engageable with said outer detents, said outer catch normally being engaged with one of said outer detents, an inner catch rotatably connected to said shaft and being engageable with said inner detent, said inner catch normally being disengaged from said inner detent, and a solenoid coupled to said catches and responsive to the slewing signal for disengaging said outer catch from said one outer detent and simultaneously engaging said inner catch with said inner detent.

19. A high speed paper advance system energizable from a source of mechanical energy for selectively advancing the paper cyclically, one line at a time, and in response to a slewing pulse, continuously, a selected number of'lines, said system being operable in response to a control pulse for stopping said paper at a predetermined point in the cyclical advance of said paper, said system comprising: a shaft energizable from the source for rotation at a constant speed about its axis; a clutch mechanically coupled between the source and said shaft for norJ mally energizing said shaft, said clutch being operable i'n response to the control pulse for de-energizing said shaft; an arm rotatably mounted on said shaft; electroJ mechanical means for selectively holding said arm sta tionary with respect to said shaft or for fixing said arm to said shaft, said electro-mechanical means normally holding said arm stationary and being responsive to the slewing pulse for fixing said arm to said shaft to rotate said arm with said shaft at said constant speed; output means mechanically coupled to said shaft and said arm for advancing the paper, said output means including mechanism for intermittently advancing the paper one line at a time when said arm is held stationary by said electromechanical means or for continuously advancing the paper the selected number of lines when said arm is fixed to said shaft by said electro-mechanical means; and mechani cal feed back means connected between said arm and said clutch for synchronizing said clutch with the advance of the paper in such a manner that de-energization of said shaft can only occur at the predetermined point in the cyclical advance of the paper.

20. The system defined in claim 19 wherein the mechanism of said output means includes a driven member rotatably mounted on said shaft and mechanically coupled to the paper for advancing the paper, said driven member being periodically rotatable through a fixed predetermined angle to cyclically advance the paper one line at a time and being rotatable through a number of predetermined angles corresponding to the selected number of lines for continuously advancing the paper the selected number of lines; and driven means rotatably mounted on said arm and mechanically coupled to said shaft for periodically rotating said driven member through said fixed predetermined angle when said arm is held stationary by said elec- Y tromechanical means and for rotating said driven member through said number of predetermined angles when said arm is fixed to said shaft by said electro-mechanical means.

21. The system defined in claim 19 wherein said clutch includes an input member mechanically coupled to the source, an output member mechanically coupled to said shaft and normally coupled to said input member, and means responsive to the control pulse for decoupling said output member from said input member; said mechanical feedback means includes a shaft mechanically coupled between said arm and said means.

Carroll et al Dec. 29, 1936 Keen June 3, 1941 UNITED STATES PATENT OFFICE CERTIFICATE 0F CORRECTION Patent No. 2,800,073 July '23, 195'? Arnold H. Block It is hereby certified that error appears .in the printed specification of the above numbered patent requiring correction and that the said Lettere Patent should read as corrected below.

Column 8, line 43, for "Dick 85" read --Dsk 85; column 9, line 64, for nthe, second occurrence, read that; column 18, line 33, for ndriven" read drver.

Signed and sealed this 26th day of November 1957,

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Cozmssioner of Patents 

